Plate locking mechanism for printing presses



May 12, 1931., w. DURRANT PLATE LOCKING MECHANISM FOR PRINTING PRESSES Filed Oct. 16, 1928 INVENTOR William Dar/1522i BY ATTORNE lll'm Patented May 12, 1931 WILLIAM DURRANT, OF PLAINFIELD, N EW JERSEY PLATE LOCKING MECHANISM FOR PRINTING PRESSES Application filed October 16, 1928. Serial No. 312,785.

My invention relates to plate locking mechanism for printingpresses and has for an object to provide an improved means for locking printing plates to aplate support.

My invention is particularly adaptable to rings are arranged in opposed pairs of semiannular form. 4

Various means have been provided for adjusting the outer sliding rings to clamping position, some of which means are shown in my Patent $51,674,426, issued June 19, 1928, and my copending applications Serial Numbers 252,462 and 252,538, filed February 7, 1928.

It is an object of the present invention to provide mechanism of simple and inexpensive construction for moving the sliding ring to clamping position to lock up the plates.

Another object of the invention is to provide means for adjusting the clamping ring with respect to the locking means. 8 Another object of the invention is to provide a device of this character in which the locking mechanism will be latched in locking position.

Another object of the invention is to provide means for guarding against the carelessness of an operative in locking up the plates and thereby insuring positive locking of the plates.

Another object of the invention is to provide a device of this character in which the thrust of the locking ring is taken up by resilient means.

Another object is to provide a locking mechanism which may be applied to an existing cylinder with a minimum of expense.

With these and other objects in view, I

shall now describe an embodiment of my inventionin connection with the accompanying drawings, and will thereafter point out the novelty and scope of my invention in the claims.

In the drawings Figure 1 is a fragmentary view, of one end of printing press cylinder with my plate locking mechanism attached thereto.

Fig. 2 is a view in longitudinal section taken on the line 22 of Fig. 3.

3 is a plan view of a portion of the press cylinder with my improved clamping mechanism attached thereto, certain parts being shown in section.

4 is a view in section taken on the line 4-4 of Fig. 2.

Fig. 5 is a view in section taken on the line 55 of Fig. 2, and

Fig. 6 is a view in perspective of a wrench used for operating the locking mechanism.

in the drawings, a portion of a press cylinder is indicated at 10 and on this cylinder is shown a fragment of a stereotype plate 11, which at its outer end is formed with a beveled edge 12 adapted to be engaged by a clamping ring 13.

This ring is preferably of semi-annular form and is secured to a central slide block lat, and also to blocks 15 adjacent opposite S0 ends thereof. These blocks engage and slide in under-cut ways 16 formed in the cylindrical face 16 of the cylinder 10. The way 16 in which the central block 14 slides has a recess 17 formed in the bottom wall 8 thereof to accommodate a link 18. A screw 19 is threaded into the block I l and its outer end is pivotally connected to the inner end of the link 18 by means of a bolt 20. The outer end of the link 18 is apertured to receive a pin 21 which depends from a disk 22. The pin is eccentrically disposed to the disk 22 and the latter is journaled in a thrust block 23, so that by turning the disk 22 in its journal, the crank pin 21 will cause the block 14 to move back or forth in the way 16.

The block 23 is provided with a central transverse slot 24 to accommodate the outer end of the link 18 and below this slot the block is formed with an arcuate slot 25, as

best shown in Fig. 5 to accommodate the lower end of the crank pin 21. This arcuate slot is concentric with the disk 22 and serves not only as a guide for the pin 4 as it moves the link 18 back and forth, but also to limit the throw of the pin. To this end the slot is lone enough to permit the pin to move throng 1 an angle of 180 degrees and. the slot is so disposed that in movin the link to its extreme inner position the pin will move slightly past a line joining the axis of disk 22 and that of pivot bolt 20. The thrust of the pin will then be taken by the block 23 and outward pressure on the link will have no tendency to force the pin back along the slot, but instead, will press the pin forward against the adjacent end wall of the slot.

The thrust block 23 is provided at the bottom with a plate 27 which serves to support the lower end of the pin 21 and hence the disk 22. he top of the block is covered by a plate 28 which overlies the disk 22. The latter is provided with a square socket 29 to receive the squared end 30 of an operating wrench 31 and the plate 23 is formed with an aperture 32 to admit the wrench end 3 The block 23 instead of being rigidly se cured to the end of the cylinder 10 is attached thereto by resilient means. 1 1 niunber of bolts 33 pass through bolt holes in the block 23 and are screwed into the end of the cylinder 10. The bolt holes, however, are enlarged to provide recesses for springs 35 which fit between the heads 3601. the bolts and the shoulders 34a formed at the bottom of the bolt holes 34. Thus, the thrust against the block is taken not by the bolts 33 but by the springs 35 on the bolts.

A latch is provided in the disk 22 to hold the locking mechanism either in clamping position or open position, thereby preventing the parts from creeping or jarring loose. To this end, the disk 22 is vertically bored to receive a spring 33 which bears at its upper end against a button 39 formed with a rounded head. The plate 28 is provided with two oppositely disposed openings 40 and 41 respectively through which this rounded head projects when the disk 23 is in one or the other of its extreme positions. In other words, when the disk has been moved to clamping position, the button 39 will enter the openin 40 and lock the parts against accidental displacement and similarly when the disk has been. moved to the unlocking position, the button 39 will enter the opening 41 on the opposite side of the plate 28. In moving the parts to locking position, the operator will turn the disk 22 until the latch 39 enters the opening 40 and he will be enabled to do this despite slight variations in the stereotype plate, owing to the fact that the thrust block is resiliently attached to the end of the press cylinder.

In order to unlock the latching means,

the wrench 31 is provided with a disk member 42 having a pair of oppositely disposed lugs 43 so that when the wrench is inserted in the socket one or the other of these lugs will engage the latch and depress it suiiiciently to permit of turning the disk 22. As a further precaution and to insure positive locking or unlocking of the mechanism at every operation, a retainer plate 44 is provided which is secured to the top of the plate 28. The plate 44 is provided with a central aperture 46 large enough to admit the disk 42 and at diametrically opposite sides of the aperture 46 are recesses 47 to receive the lugs 43. Thus, in applying the wrench, it must always be placed with the lugs 43 in a definite position with respect to the thrust block and after the lugs 43 have passed through the recesses 47 and have depressed he latch 39, they may be turned, because that portion of the plate 44 which forms the rim of the opening 46' is under-cut as indicated at 49. Once the wrench has been turned it cannot be removed from the locking mechanism until it has been turned sufficiently to bring the lugs 43 into alinement with the recesses 47. In other words, the wrench cannot be removed until the locking device has either been moved to complete locking position or to complete latch 39 is positioned with respect to the openings 47 as to be alined with one of said openings when the disk is in looking position and with the other opening when it is in unlocked position.

In operation, after a plate 11 has been placed on the cylinder, the ring clamp 13 is moved into locking position by a turn of the wrench 31 and similarly it will be positively unlocked. by a turn of the wrench 31 in the opposite direction. In order to allow for adjustment between the locking mechanism and the block 14, the screw 19 is provided. To effect such adjustment, the bolt 20 is removed disconnecting the link 18 from the head of the screw 19 and the screw may then be turned in the block 14 to the desired extent.

In applying my locking device to an existing press the only work that need be done on the cylinder is to mill out the recesses 17 and bore and tap holes for the bolts 33.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a locking mechanism of the character described, a thrust block, a clamping member movable with respect to the thrust block, a crank journal in the thrust block and including a crank pin, means operatively connecting the clamping member to the pin, and a guide engaging the free end of the crank pin.

In a locking mechanism of the character described, a thrust block, a clamping member movable with respect to the thrust block, a

unlocking position. The

crank journaled in the thrust block and including a crank pin, and means operatively connecting the clamping member to the pin, the thrust block being formed with a slot to guide the crank pin and limit its movement.

3. In a locking mechanism of the charactor described, a thrust block, a clamping member, a crank for moving said member into clamping position, said crank comprising a cylindrical head and a pin projecting eccentrically from said head, and a link pivotally connected at one end to the crank pin and at the other to said clamping member, the thrust block providing a bearing for said head and being formed with an opposed concentric arcual slot to receive and guide the free end of said crank pin.

4. In a locking mechanism of the character described, a thrust block, a clamping member, a crank for moving said member into clamping position, said crank comprising a cylindrical head and a pin projecting eccentrically from said head, a link pivotally connected at one end to the crank pin and at the other to said clamping member, the thrust block providing a bearing for said head and being "formed with an opposed concentric arcual slot to receive and guide the free end of said crank pin, said slot being arranged to limit movement of the pin, when the crank is turned in clamping direction, after the longitudinal axis of the link has moved past alinement with the axis of the pin.

5. In a locking mechanism of the character described, a thrust block, a clamping member, a crank for moving said member into clamping position, said crank comprising a cylindrical head and a pin projecting eccentrically from said head, a link pivotally connected at one end to the crank pin and at the other to said clamping member, the thrust block providing a bearing for said head and being formed with an opposed concentric a-rcual slot to receive and guide the free end of said crank pin, and means for adjusting the clamping member with respect to the link.

6. In a locking mechanism of the charac ter described, a thrust block, a clamping member, a crank journaled in said block and adapted to move said clamping member into clamping position, a guide in the thrust block for guiding the movement of said crank, and a latch for holding the crank when said member is in clamping position.

7 In combination with a printing press cylinder, a clamping member slidable thereon, a thrust block yieldably secured to the cylinder, a crank journaled in the thrust block and adapted to slide said member, the crank being formed with means for applying a wrench thereto, and means for preventing removal of the wrench until the crank has been moved through a predetermined angle.

8. In combination with a printing press two positions, a wrench adapted to engage and turn the crank, and means carried by the wrench for unlatching the crank.

9. In combination with a printing press cylinder a clamping member slidable thereon, a thrust block yieldably secured to the cylinder, a crank journaled in the thrust block and adapted to slide said member into and out of clamping position on the cylinder, means for latching the crank in either of two positions, a wrench adapted to engage and turn the crank, means carried by the wrench for unlatching the crank, and means for preventing removal of the wrench until the crank has been moved to one of said two positions.

10. In a locking mechanism of the character described, an operating crank comprising a cylindrical head and a pin eccentrically mounted thereon, a link pivotally engaging the pin, and a bearing block formed with a transverse slot to receive the link and with a bearing for the crank head on one side of the slot and an arcuate slot to receive the pin on the opposite side of the transverse slot.

11. In a locking mechanism of the character described, an operating crank comprising a cylindrical head and a pin eccentrically mounted thereon, a link pivotally engaging the pin, a bearing block formed with a transverse slot to receive the link and with a bear ing for the crank head on one side of the slot and an arcuate slot to receive the pin on the opposite side of the transverse slot, and a plate at each side of the block to retain the crank therein, the crank head being formed with a socket to receive a wrench and one of said plates being formed with an aperture to provide access to said socket.

In testimony whereof, I have signed this specification.

WILLIAM DURRANT. 

